1. Field of the Invention
This invention relates to the extraction of substances from aqueous solution and to mixtures of fluorocarbon solvents used in such extraction.
2. Description of the Prior Art
Many chemical processes as well as other types of industrial operations require the recovery of substances from aqueous solution. One means for accomplishing such recovery is by solvent extraction. In such a procedure, the aqueous solution is contacted with an immiscible solvent in which the dissolved material (solute) also exhibits solubility. Since the two liquids are immiscible, some form of agitation, such as stirring, shaking or counter-current flow is used to bring them into intimate contact whereupon solute dissolves in the non-aqueous phase. If the liquids are then allowed to stand, two distinct layers are formed which can be separated by decantation.
Solvent extraction as above described has long been used to remove dissolved materials from aqueous solution and is a common separation step in laboratory procedures. It provides a simple and convenient means for removing by-product from a reaction medium. However, if the solute is the desired end product, or if it is necessary to recover solute for disposal or re-use--as would probably be the case in an industrial operation--a further separation step must be carried out. In many instances, this would be some form of distillation separation, which means the expenditure of considerable energy and higher production costs.